The invention relates to a mechanical connection of sheet-type panels, as are typically used for a floor covering, such as parquet or laminate flooring, or for ceiling and wall tiling.
In all cases, the individual panels can be joined through a mechanical connection, i.e., interlocking, to form a flat surface, so the panels can be laid without adhesives or additional mechanical fastening elements, such as screws or nails. A particular advantage of this is that the panels can be laid without adhesive bonding, and can therefore be removed.
JP 3-169967 A, on which the present invention is based, describes a mechanical connection of flooring panels. Along a first side edge, the panels are provided with a groove, which is formed by an upper lip and a lower lip and extends parallel to the side edge. Embodied on an opposite side edge of the further, second panel is a tongue, which extends parallel to this side edge. A depression having an interlocking surface that extends at an incline with respect to the top side of the panel is embodied in the groove. A corresponding interlocking element, which has an interlocking surface that extends at an incline with respect to the top side, is embodied at the tongue. Furthermore, fitting surfaces that extend parallel to the top side and serve as abutments for the interlocking surfaces of the groove depression and the interlocking element of the tongue are embodied in the groove and at the tongue, at the end facing the respective side edge. In the direction parallel to the top side, the upper lip covers the interlocking surface embodied opposite it in the groove. In the interlocked state of the connection, the fitting surfaces and the interlocking surfaces fit closely together in pairs in order to keep the side edges in contact. Through the cooperation of the fitting surfaces and the interlocking surfaces, the impacting side edges of two panels rest tightly against one another, forming a virtually gap-free connection.
Further mechanical panel connections are known from the prior art disclosed in WO 94/26999, WO 96/27721, WO 97/47834 and WO 98/58142.
A common feature of the mechanical panel connections known from the prior art is that they permit a reliable mechanical interlocking in the direction parallel to the top side of the panels, yet they possess a low rigidity with respect to a rotation of the panel at the adjacent side edges. Hence, the panels can be pivoted relative to one another fairly easily, leading to a loosening of the mechanical connection. In the prior art, this is even desirable to a certain extent for simple panel laying. On the other hand, these known panels possess a sufficient rigidity in terms of the aforementioned tilting and pivoting of the panels relative to one another, but the panel interlocking of the connection is inadequately rigid. In addition, the fitting in the direction perpendicular to the top side is limited to only one fitting-surface pair, so the adjacent side edges do not match exactly in height, thus forming a noticeable step.
The technical problem facing the invention, therefore, is to provide a mechanical connection of panels that is distinguished by improved interlocking and stability properties.
In accordance with the invention, the outlined technical problem is solved by a connection possessing the features of the preamble to claim 1, namely that a recess formed by a surface extending essentially perpendicular to the top side and a fitting surface extending parallel to the top side is provided in the region of the side edge, and an upper lip formed by the top side, a surface extending essentially perpendicular to the top side and a fitting surface extending parallel to the top side is provided in the region of the side edge, with the fitting surfaces and the other surfaces resting against one another in the interlocked state of the connection.
In accordance with the invention, the two panels are stabilized against tilting or pivoting along the side edges in the interlocked state by the additional fitting surfaces in the region of the recess. The interlocking, in contrast, is effected by the pair of interlocking surfaces and the pair of fitting surfaces disposed at the end facing the side edges, and acting as abutments. Therefore, the force generated by the interlocking surfaces effectively prevents the two panels from moving apart in a plane parallel to the top sides and perpendicular to the side edges. Thus, different fitting-surface pairs assure the interlocking, on the one hand, and the stabilization of the orientation of the two panels, on the other hand.
A further advantage of the mechanical panel connection according to the invention is that the fitting surface in the region of the recess of the first panel and at the upper lip of the second panel permits a very precise adaptation of the top sides of the two panels relative to one another, which effectively prevents the occurrence of uneven areas at the adjacent side edges.
In a preferred manner, the fitting surface that is disposed opposite the interlocking surface inside the groove of the first side edge extends at an incline with respect to the top sides. Consequently, the tongue to be inserted is guided during the joining process of the two panels.
If, in contrast, these fitting surfaces extend parallel to the top sides, an additional fitting is advantageously effected in the vertical direction, in addition to the fitting-surface pair of the invention.
It is further preferable for the end surface of the upper lip and the end surface of the interlocking lip of the first side edge to be arranged in essentially one plane. In this case, joining the panels by means of force prevents the impact force from being absorbed by only one of the two lips, resulting in a more uniform joining of the two panels.